Carbon nanotube composite and method for preparing the same

Abstract

The present disclosure describes to a method embodiment for preparing a carbon nanotube composite that includes performing a first ultrasonic treatment on a first mixture containing a carbon nanotube (CNT) fiber and an acid to form a carbon nanotube fiber swollen body, and performing a second ultrasonic treatment on a second mixture containing the carbon nanotube fiber swollen body, an aromatic monomer, and an initiator to form a carbon nanotube composite including a surface coated with an aromatic monomer-derived conductive polymer, and an embodiment of the carbon nanotube composite prepared therefrom.

What is claimed is: 
     
         1 . A method for preparing a carbon nanotube composite, the method comprising:
 performing a first ultrasonic treatment on a first mixture, the first mixture containing a carbon nanotube (CNT) fiber and an acid, to form a carbon nanotube fiber swollen body; and   performing a second ultrasonic treatment on a second mixture, the second mixture containing the carbon nanotube fiber swollen body, an aromatic monomer, and an initiator, to form a carbon nanotube composite including a surface coated with an aromatic monomer-derived conductive polymer.   
     
     
         2 . The method of  claim 1 , wherein the acid comprises an inorganic acid. 
     
     
         3 . The method of  claim 2 , wherein the acid contains sulfuric acid and nitric acid. 
     
     
         4 . The method of  claim 3 , wherein the acid contains the sulfuric acid and the nitric acid in a volume ratio from 2:1 to 4:1. 
     
     
         5 . The method of  claim 1 , wherein the first ultrasonic treatment is performed with an ultrasonic wave having a first frequency in a range from 20 kHz to 50 kHz, for 2 to 4 hours, and wherein the second ultrasonic treatment is performed with an ultrasonic wave having a second frequency in a range from 30 kHz to 50 kHz, for 2 to 4 hours. 
     
     
         6 . The method of  claim 1 , wherein the conductive polymer contains a repeating unit containing nitrogen or sulfur, inside or outside an aromatic ring in a main chain. 
     
     
         7 . The method of  claim 6 , wherein the conductive polymer includes one of or any combination of an aniline-based polymer, a pyrrole-based polymer, a thiophene polymer, and a poly(phenylene sulfide)-based polymer. 
     
     
         8 . The method of  claim 1 , wherein the second mixture contains 20000 to 25000 parts by weight of the aromatic monomer relative to 100 parts by dry weight of the carbon nanotube fiber swollen body. 
     
     
         9 . The method of  claim 1 , wherein a linear density of the carbon nanotube fiber swollen body is 110 to 140% of a linear density of the carbon nanotube fiber. 
     
     
         10 . The method of  claim 1 , wherein an average diameter of a cross-section perpendicular to a longitudinal direction of the carbon nanotube fiber swollen body is 150 to 250% of an average diameter of a cross-section perpendicular to a longitudinal direction of the carbon nanotube fiber. 
     
     
         11 . The method of  claim 1 , wherein an average pore diameter of the carbon nanotube fiber swollen body is 120 to 160% of an average pore diameter of the carbon nanotube fiber. 
     
     
         12 . The method of  claim 1 , wherein a surface oxygen content of the carbon nanotube fiber swollen body is 150 to 450% of a surface oxygen content of the carbon nanotube fiber. 
     
     
         13 . A carbon nanotube composite comprising:
 a carbon nanotube; and   an aromatic monomer-derived conductive polymer coated along a surface of the carbon nanotube in a longitudinal direction,   wherein a linear density of the carbon nanotube composite is equal to or greater than 20 g/km.   
     
     
         14 . The carbon nanotube composite of  claim 13 , wherein the conductive polymer comprises one of or any combination of an aniline-based polymer, a pyrrole-based polymer, a thiophene polymer, and a poly(phenylene sulfide)-based polymer. 
     
     
         15 . The carbon nanotube composite of  claim 13 , wherein specific electric conductance of the carbon nanotube composite is in a range from 700 to 1,000 Sm 2 /kg and a surface oxygen content of the carbon nanotube composite is in a range from 20 to 30 atomic %. 
     
     
         16 . The carbon nanotube composite of  claim 13 , wherein an elongation is in a range from 10 to 20%, and an average pore diameter is in a range from 180 to 250 Å. 
     
     
         17 . An electrode for a supercapacitor comprising the carbon nanotube composite of  claim 13 . 
     
     
         18 . A supercapacitor comprising an electrode, wherein the electrode comprises the carbon nanotube composite of  claim 13 . 
     
     
         19 . The supercapacitor of  claim 18 , wherein length capacitance (C L ) of the supercapacitor is equal to or greater than 80 mF/cm, specific capacitance (C SP ) of the supercapacitor is equal to or greater than 300 F/g, and a capacitance change after 90° bending of the supercapacitor is equal to or less than 5%.